The present invention relates generally to electric utility apparatus and, more particularly, to an apparatus for modifying an existing electric equipment to incorporate additional auxiliary components.
Electric meters and other wall-mounted electrical equipment have been used for many years by electric utility companies and others to measure the energy consumption of their customers or to perform other functions. The various types of wall mounted electrical equipment includes kilowatt-hour meters, load management terminals, transponders and other equipment related to either the measurement of electric energy consumption or power line communications equipment. In its simplest form, a kilowatt-hour meter incorporates an energy measurement apparatus that is responsive to the consumption of electrical energy and a registering device that is able to visually indicate or electrically communicate the cumulative consumption of the measured quantity. The registering device which is generally a dial indicator register, a cyclometer register or an electonic register, enables the consumer or a meter reader to visually determine the accumulated kilowatt-hours of energy consumption used by the consumer at whose location the electrical meter is located. Typical kilowatt-hour meters that are known to those skilled in the art utilize a rotatable disk that rotates in response to electrical energy consumption. The rotatable disk revolves about an axis that is appropriately coupled, through a plurality of gears and shafts, to a register.
The most commonly used type of register used with an electric utility meter typically comprises a plurality of shafts with each shaft connected to a dial indicator, or pointer. The shafts extend through holes in a faceplate of the register and the faceplate is provided with indicia that enables a visual determination of the numeric values corresponding to the positions of each dial. The register's shafts are typically associated in a decade relationship so that the cumulative energy consumption can be readily observed from the positions of the dial indicators with respect to their associated indicia. U.S. Pat. No. 3,178,110 which issued to Knecht et al. on Apr. 13, 1965 discloses a meter register. Many other types of registers are known to those skilled in the art. For example, cyclometer registers incorporate a plurality of drums on which numerical indicia are imposed. The indicia drums rotate in response to electrical energy usage and the cumulative value of consumption at any time can be read directly from the front portion of the register. Also, electronic registers can be used in conjunction with kilowatt hour meters. These registers provide digital representations of cumulative electrical energy usage by being operatively associated with a pulse counting device and related electronic circuitry.
In recent years, many technological advances have occurred in the field of electrical metering. For example, time-of-use (TOU) meters have been developed that enable an electric utility to incorporate a multirate billing system that varies as a function of the time of day or day of the year when the electrical energy is consumed. A multiple rate meter is disclosed in U.S. Pat. No. 4,081,746 which issued to Snyder et al. on Mar. 28, 1978 and an improved clutch mechanism for time of day registers is disclosed in U.S. Pat. No. 4,307,341 which issued to Benbow et al. on Dec. 22, 1981. Furthermore, demand meters have been developed that measure the consumer's electrical power demands over predetermined periods of time during the building period. A demand meter is disclosed in U.S. Pat. No. 3,913,014, which issued to Halstead on Oct. 14, 1975 and an on-peak watt-hour demand meter with disc loading compensation is disclosed in U.S. Pat. No. 4,156,184, which issued to Benbow on May 22, 1979.
Besides kilowatt-hour meters, many other types of electrical equipment are used by electrical utilities. For example, load management terminals can be located at a consumer's residence for the purpose of load shedding during periods of peak demand. In a typical system of this type, the electric utility would send modulated signals to particular load management terminals that command the terminals to shed specific non-essential loads at the customer's residence. Some load management terminals only have the ability to receive signals which are transmitted on the power line and to respond to commands received in this manner from a central location. Other load management terminals also have the capability of both transmitting and receiving power line communication signals. This capability permits the load management terminal to not only respond to commands received from a central utility location, but also to transmit data from the consumer's residence to a central location. This data would typically comprise meter reading data or other status-related signals.
Many recent developments in the field of electrical measurement and powerline communications in recent years relate to the increased use of electronic circuitry within the kilowatt-hour meter. The use of solid state components and microprocessors within electric equipment, such as meters or load management terminals, is rapidly becoming common place. The use of microprocessors, or microcomputers, within these types of electrical equipment vastly increases its capabilities and expands the type of information that it can provide to both the electric utility and the consumer. For example, in order to display the many types of numeric information that can be provided by a kilowatt-hour meter, electronic registers have been developed. These electronic registers display data on an alphameric panel which is able to sequentially display a plurality of values, whereas a mechanical register requires a single dial indicator and associated shaft for every digit of a measured quantity. Microprocessor permit electrical equipment, which is located at a consumer's residence, to perform complex demodulation and modulation of powerline communication signals, accurately read the meter and perform load shedding operations.
When an electric utility desires to upgrade its metering or load control capability, it faces a potentially expensive procedure. For each conventional kilowatt-hour meter that is replaced by a more sophisticated meter, the utility must not only consider the additional cost for the more technologically advanced meter, but also the potential loss due to their increased inventory of the unused meters. When a conventional watt-hour meter is replaced by a more sophisticated meter, some of the capabilities of the simpler meter are necessarily reproduced in the new meter. This represents an unnecessary expense because a portion of the cost for the new meter relates to replacement of components that were part of the replaced meter.
Therefore, when an electric utility replaces an existing electrical apparatus with a more complicated and technologically advanced device, a portion of the incurred expense represents the replacement of existing components with redundant components in the new device. It would therefore be economically advantageous if an existing apparatus, such as a watt-hour meter, could be upgraded without the need to replace its existing components that would also be required in the new meter. For example, if a meter could be upgrade by merely adding axiliary equipment, significant savings could be realized.
The present invention will be described in terms of its particular application to a kilowatt hour meter. However, it should be understood that alternative embodiments of the present invention could also be used to provide a means for attaching and supporting auxiliary components to existing electrical apparatus. The support structure of the present invention could be used, for example, in association with kilowatt hour meters, load management terminals, metering and control transponders, and many other types of wall-mounted electrical apparatus that is commonly used by electrical utility companies. Furthermore, although a particular embodiment of the present invention utilizes a ring-shaped base as it means for attaching the support structure to the base of the electrical apparatus, it should be understood that various other shapes of the attachment means can be used. Also, the ring-shaped base of the support structure is described as being attachable to the base by means of a plurality of latches. It should be understood that many alternative attaching means, such as screws, are also within the scope of the present invention. For convenience, the present invention is described herein in terms of a particular embodiment that is applicable for use in association with kilowatt hour meters.
The present invention relates to an apparatus for upgrading existing electrical apparatus, such as meters, with auxiliary electronic equipment. It comprises a support structure that has an attachment means, such as a base ring, shaped to fit into the base of the electrical apparatus in rotatable association therewith. Many existing meter bases have a pair of molded rings in their bases. These rings, or functionally similar configurations, cooperate with a gsket in order to provide an effective seal between the cover and the base of a kilowatt-hour meter. When applied in association with a kilowatt hour meter that has a base with molded rings, the base ring of the present invention is shaped to fit with the molded rings in such a way so as to prevent relative motion in all directions except in the direction of rotation about the central axis of symmetry of both the base ring and the molded rings of the meter's base.
The base ring of the present invention is provided with a plurality of latches that are rotatably connected to it. Each of the latches, when rotated about their individual centers of rotation, move their latch portions radically inward in such a way so as to abut a portion of the meter structure. When the latches are rotated about their individual axes of rotation, they prevent the base ring from rotating about its central axis of symmetry because they abut components of the meter base structure. They also are engaged between the base ring and a frame portion of the meter structure. Therefore, the base ring is attached to the meter base in such a way so as to prevent its rotation about its central axis symmetry and its movement in a direction away from the meter base. It should be understood that, although these latches provide a convenient way of attaching the support structure of the present invention to the apparatus, alternative methods of attachment are also possible. For example, the base ring could be screwed or bolted to the meter base.
The base ring of the present invention is provided with a plurality of posts that are attached to it and extend in a direction away from the meter's base. Each of the posts has one of its ends attached to the base ring and extends in a direction which is generally parallel to the central axis of symmetry of the base ring. These posts are used to support one or more support plates. Each mounting plate is attached to the posts in such a way so as to hold the mounting plate in a configuration which is generally perpendicular to the central axis of symmetry of the base ring. The primary function of the posts is to support the support plates at a position which extends beyond the original components of the meter. This enables additional electrical devices to be attached to the support plates in a position which does not interfere with the components of the original meter. It should be understood that the support plates would normally comprise a combination of plates, brackets and circuit boards.
The support plates of the present invention can be provided with an opening that is generally aligned with the indicia portion of the register's front plate when the present invention is attached to a meter. The dial indicators of the register and the opening in the support plates are aligned along a line that is generally parallel to the central axis of symmetry of the base ring. Since the mechanical register of a typical kilowatt-hour meter is generally disposed in a configuration that is readily visible in a direction perpendicular to the base of the meter, the openings in the support plates of the present invention permit visual observation of the dial indicators through the support plate structure. Of course, it should be understood that the openings in the support plates are not required if no visual register is to be disposed behind them. In applications of the present invention that relate to load management terminals, transponders or other electrical apparatus which does not utilize a manually readable register, the support plates of the present invention can be incorporated without the use of these openings.
Besides supporting a plurality of electronic devices, the support plates of the present invention are also able to provide support for an additional electronic register that can be added, as auxiliary equipment, to an existing kilowatt-hour meter. When an electronic register is used in accordance with the present invention, a pulse initiator is attached to the frame of the existing meter and a flexible conductor is used to provide electrical communications between the pulse initiator and the electronic register. Of course, it should be understood that the present invention is applicable with many different types of electrical apparatus. In some applications, the pulse initiator may be mounted on a remote meter and the signals form the pulse initiator are communicated to the electrical apparatus comprising the present invention along signal wires. This would be a typical application in situations where the present invention is used in conjunction with load management terminals, either pluggable or surface mounted, which do not contain their own meters. Various types of pulse initiators are known to those skilled in the art. A photoelectric pulse initiator is disclosed in U.S. Pat. No. 4,047,024, which issued to Henderson on Sept. 6, 1977. A direction sensitive opto-electronic pulse initiator for electrical meters is disclosed in U.S. Pat. No. 4,034,292, which issued to McClelland on July 5, 1977 and a direct input photoelectric pulse initiator for meter telemetry and recording systems is disclosed in U.S. Pat. No. 3,943,498, which issued to McClelland et al. on Mar. 9, 1976. Furthermore, flexible conductors are used to provide electrical communication between the existing portions of the original meter and the additional electronic components attached to the support plates.
The radial and longitudinal dimensions of the support structure of the present invention permit a cover to fit over the support structure and be attached to the base of the meter. Although the cover of the present invention is generally larger, in a longitudinal direction, than the original cover used by the existing watt-hour meter, its radial dimensions remain generally the same. The increased longitudinal dimension of the meter cover is related to the additional electronic equipment supported by the support plates and posts of the present invention. The cover generally has a transparent portion disposed in alignment with the opening of the support plates and the indicia that are associated with the dial indicators of the mechanical register. This permits and observer to view the dial indicators of the mechanical register, or the display of an electronic register, by looking along a line of sight through the transparent portion of the meter cover, the openings in the support plates and the indicia portion of the faceplate on the mechanical register. Of course, it should be understood that, in many cases, the entire cover is transparent. Furthermore, in some applications it is beneficial to use a generally transparent cover with portions of the cover being painted in order to interfere with solar heat that would normally pass through the transparent cover and disadvantageously raise the temperature within the electrical apparatus.
It should be understood that an electrical apparatus, such as a kilowatt-hour meter, made in accordance with the present invention can incorporate electronic components that are related to many different capabilities that are provided by auxiliary equipment added to the existing apparatus. The electronic components which are supported by the support plates of the present invention can provide demand metering capabilities, time of use metering, electronic registering capabilities, load control of external devices or any additional equipment that is used to upgrade existing electrical devices.